1 files changed, 73 insertions, 0 deletions
diff --git a/src/random.rs b/src/random.rs
new file mode 100644
index 0000000..334b6bf
--- /dev/null
+++ b/src/random.rs
@@ -0,0 +1,73 @@
+use rand::{Rng, SeedableRng, TryRng, rngs::SmallRng};
+
+mod tortuise {
+	#[link(wasm_import_module = "tortuise")]
+	unsafe extern "C" {
+		pub safe fn random_u64() -> u64;
+	}
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct TortuiseRng(SmallRng);
+
+impl TortuiseRng {
+	pub fn new() -> Self {
+		Self::seed_from_u64(tortuise::random_u64())
+	}
+}
+
+impl Default for TortuiseRng {
+	fn default() -> Self {
+		Self::new()
+	}
+}
+
+impl SeedableRng for TortuiseRng {
+	type Seed = <SmallRng as SeedableRng>::Seed;
+
+	fn from_seed(seed: Self::Seed) -> Self {
+		Self(SmallRng::from_seed(seed))
+	}
+
+	fn seed_from_u64(state: u64) -> Self {
+		Self(SmallRng::seed_from_u64(state))
+	}
+
+	fn from_rng<R: Rng + ?Sized>(rng: &mut R) -> Self {
+		Self(SmallRng::from_rng(rng))
+	}
+
+	fn try_from_rng<R: TryRng + ?Sized>(rng: &mut R) -> Result<Self, R::Error> {
+		Ok(Self(SmallRng::try_from_rng(rng)?))
+	}
+
+	fn fork(&mut self) -> Self
+	where
+		Self: Rng,
+	{
+		Self(self.0.fork())
+	}
+
+	fn try_fork(&mut self) -> Result<Self, <Self as TryRng>::Error>
+	where
+		Self: TryRng,
+	{
+		Ok(Self(self.0.try_fork()?))
+	}
+}
+
+impl TryRng for TortuiseRng {
+	type Error = <SmallRng as TryRng>::Error;
+
+	fn try_next_u32(&mut self) -> Result<u32, Self::Error> {
+		self.0.try_next_u32()
+	}
+
+	fn try_next_u64(&mut self) -> Result<u64, Self::Error> {
+		self.0.try_next_u64()
+	}
+
+	fn try_fill_bytes(&mut self, dst: &mut [u8]) -> Result<(), Self::Error> {
+		self.0.try_fill_bytes(dst)
+	}
+}